
/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_http.h>


static void ngx_http_read_client_request_body_handler(ngx_http_request_t *r);
static ngx_int_t ngx_http_do_read_client_request_body(ngx_http_request_t *r);
static ngx_int_t ngx_http_write_request_body(ngx_http_request_t *r,
                                             ngx_chain_t *body);
static ngx_int_t ngx_http_read_discarded_request_body(ngx_http_request_t *r);
static ngx_int_t ngx_http_test_expect(ngx_http_request_t *r);


/*
 * on completion ngx_http_read_client_request_body() adds to
 * r->request_body->bufs one or two bufs:
 *    *) one memory buf that was preread in r->header_in;
 *    *) one memory or file buf that contains the rest of the body
 */

ngx_int_t
ngx_http_read_client_request_body(ngx_http_request_t *r,
                                  ngx_http_client_body_handler_pt post_handler)
{
  size_t                     preread;
  ssize_t                    size;
  ngx_buf_t                 *b;
  ngx_chain_t               *cl, **next;
  ngx_temp_file_t           *tf;
  ngx_http_request_body_t   *rb;
  ngx_http_core_loc_conf_t  *clcf;

  r->main->count++;

  if (r->request_body || r->discard_body) {
    post_handler(r);
    return NGX_OK;
  }

  if (ngx_http_test_expect(r) != NGX_OK) {
    return NGX_HTTP_INTERNAL_SERVER_ERROR;
  }

  rb = ngx_pcalloc(r->pool, sizeof(ngx_http_request_body_t));
  if (rb == NULL) {
    return NGX_HTTP_INTERNAL_SERVER_ERROR;
  }

  r->request_body = rb;

  if (r->headers_in.content_length_n < 0) {
    post_handler(r);
    return NGX_OK;
  }

  clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

  if (r->headers_in.content_length_n == 0) {

    if (r->request_body_in_file_only) {
      tf = ngx_pcalloc(r->pool, sizeof(ngx_temp_file_t));
      if (tf == NULL) {
        return NGX_HTTP_INTERNAL_SERVER_ERROR;
      }

      tf->file.fd = NGX_INVALID_FILE;
      tf->file.log = r->connection->log;
      tf->path = clcf->client_body_temp_path;
      tf->pool = r->pool;
      tf->warn = "a client request body is buffered to a temporary file";
      tf->log_level = r->request_body_file_log_level;
      tf->persistent = r->request_body_in_persistent_file;
      tf->clean = r->request_body_in_clean_file;

      if (r->request_body_file_group_access) {
        tf->access = 0660;
      }

      rb->temp_file = tf;

      if (ngx_create_temp_file(&tf->file, tf->path, tf->pool,
                               tf->persistent, tf->clean, tf->access)
          != NGX_OK)
      {
        return NGX_HTTP_INTERNAL_SERVER_ERROR;
      }
    }

    post_handler(r);

    return NGX_OK;
  }

  rb->post_handler = post_handler;

  /*
   * set by ngx_pcalloc():
   *
   *     rb->bufs = NULL;
   *     rb->buf = NULL;
   *     rb->rest = 0;
   */

  preread = r->header_in->last - r->header_in->pos;

  if (preread) {

    /* there is the pre-read part of the request body */

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "http client request body preread %uz", preread);

    b = ngx_calloc_buf(r->pool);
    if (b == NULL) {
      return NGX_HTTP_INTERNAL_SERVER_ERROR;
    }

    b->temporary = 1;
    b->start = r->header_in->pos;
    b->pos = r->header_in->pos;
    b->last = r->header_in->last;
    b->end = r->header_in->end;

    rb->bufs = ngx_alloc_chain_link(r->pool);
    if (rb->bufs == NULL) {
      return NGX_HTTP_INTERNAL_SERVER_ERROR;
    }

    rb->bufs->buf = b;
    rb->bufs->next = NULL;

    rb->buf = b;

    if ((off_t) preread >= r->headers_in.content_length_n) {

      /* the whole request body was pre-read */

      r->header_in->pos += (size_t) r->headers_in.content_length_n;
      r->request_length += r->headers_in.content_length_n;
      b->last = r->header_in->pos;

      if (r->request_body_in_file_only) {
        if (ngx_http_write_request_body(r, rb->bufs) != NGX_OK) {
          return NGX_HTTP_INTERNAL_SERVER_ERROR;
        }
      }

      post_handler(r);

      return NGX_OK;
    }

    /*
     * to not consider the body as pipelined request in
     * ngx_http_set_keepalive()
     */
    r->header_in->pos = r->header_in->last;

    r->request_length += preread;

    rb->rest = r->headers_in.content_length_n - preread;

    if (rb->rest <= (off_t) (b->end - b->last)) {

      /* the whole request body may be placed in r->header_in */

      rb->to_write = rb->bufs;

      r->read_event_handler = ngx_http_read_client_request_body_handler;

      return ngx_http_do_read_client_request_body(r);
    }

    next = &rb->bufs->next;

  } else {
    b = NULL;
    rb->rest = r->headers_in.content_length_n;
    next = &rb->bufs;
  }

  size = clcf->client_body_buffer_size;
  size += size >> 2;

  if (rb->rest < size) {
    size = (ssize_t) rb->rest;

    if (r->request_body_in_single_buf) {
      size += preread;
    }

  } else {
    size = clcf->client_body_buffer_size;

    /* disable copying buffer for r->request_body_in_single_buf */
    b = NULL;
  }

  rb->buf = ngx_create_temp_buf(r->pool, size);
  if (rb->buf == NULL) {
    return NGX_HTTP_INTERNAL_SERVER_ERROR;
  }

  cl = ngx_alloc_chain_link(r->pool);
  if (cl == NULL) {
    return NGX_HTTP_INTERNAL_SERVER_ERROR;
  }

  cl->buf = rb->buf;
  cl->next = NULL;

  if (b && r->request_body_in_single_buf) {
    size = b->last - b->pos;
    ngx_memcpy(rb->buf->pos, b->pos, size);
    rb->buf->last += size;

    next = &rb->bufs;
  }

  *next = cl;

  if (r->request_body_in_file_only || r->request_body_in_single_buf) {
    rb->to_write = rb->bufs;

  } else {
    rb->to_write = rb->bufs->next ? rb->bufs->next : rb->bufs;
  }

  r->read_event_handler = ngx_http_read_client_request_body_handler;

  return ngx_http_do_read_client_request_body(r);
}


static void
ngx_http_read_client_request_body_handler(ngx_http_request_t *r)
{
  ngx_int_t  rc;

  if (r->connection->read->timedout) {
    r->connection->timedout = 1;
    ngx_http_finalize_request(r, NGX_HTTP_REQUEST_TIME_OUT);
    return;
  }

  rc = ngx_http_do_read_client_request_body(r);

  if (rc >= NGX_HTTP_SPECIAL_RESPONSE) {
    ngx_http_finalize_request(r, rc);
  }
}


static ngx_int_t
ngx_http_do_read_client_request_body(ngx_http_request_t *r)
{
  size_t                     size;
  ssize_t                    n;
  ngx_buf_t                 *b;
  ngx_connection_t          *c;
  ngx_http_request_body_t   *rb;
  ngx_http_core_loc_conf_t  *clcf;

  c = r->connection;
  rb = r->request_body;

  ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0,
                 "http read client request body");

  for ( ;; ) {
    for ( ;; ) {
      if (rb->buf->last == rb->buf->end) {

        if (ngx_http_write_request_body(r, rb->to_write) != NGX_OK) {
          return NGX_HTTP_INTERNAL_SERVER_ERROR;
        }

        rb->to_write = rb->bufs->next ? rb->bufs->next : rb->bufs;
        rb->buf->last = rb->buf->start;
      }

      size = rb->buf->end - rb->buf->last;

      if ((off_t) size > rb->rest) {
        size = (size_t) rb->rest;
      }

      n = c->recv(c, rb->buf->last, size);

      ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0,
                     "http client request body recv %z", n);

      if (n == NGX_AGAIN) {
        break;
      }

      if (n == 0) {
        ngx_log_error(NGX_LOG_INFO, c->log, 0,
                      "client closed prematurely connection");
      }

      if (n == 0 || n == NGX_ERROR) {
        c->error = 1;
        return NGX_HTTP_BAD_REQUEST;
      }

      rb->buf->last += n;
      rb->rest -= n;
      r->request_length += n;

      if (rb->rest == 0) {
        break;
      }

      if (rb->buf->last < rb->buf->end) {
        break;
      }
    }

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0,
                   "http client request body rest %O", rb->rest);

    if (rb->rest == 0) {
      break;
    }

    if (!c->read->ready) {
      clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);
      ngx_add_timer(c->read, clcf->client_body_timeout);

      if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
        return NGX_HTTP_INTERNAL_SERVER_ERROR;
      }

      return NGX_AGAIN;
    }
  }

  if (c->read->timer_set) {
    ngx_del_timer(c->read);
  }

  if (rb->temp_file || r->request_body_in_file_only) {

    /* save the last part */

    if (ngx_http_write_request_body(r, rb->to_write) != NGX_OK) {
      return NGX_HTTP_INTERNAL_SERVER_ERROR;
    }

    b = ngx_calloc_buf(r->pool);
    if (b == NULL) {
      return NGX_HTTP_INTERNAL_SERVER_ERROR;
    }

    b->in_file = 1;
    b->file_pos = 0;
    b->file_last = rb->temp_file->file.offset;
    b->file = &rb->temp_file->file;

    if (rb->bufs->next) {
      rb->bufs->next->buf = b;

    } else {
      rb->bufs->buf = b;
    }
  }

  if (rb->bufs->next
      && (r->request_body_in_file_only || r->request_body_in_single_buf))
  {
    rb->bufs = rb->bufs->next;
  }

  r->read_event_handler = ngx_http_block_reading;

  rb->post_handler(r);

  return NGX_OK;
}


static ngx_int_t
ngx_http_write_request_body(ngx_http_request_t *r, ngx_chain_t *body)
{
  ssize_t                    n;
  ngx_temp_file_t           *tf;
  ngx_http_request_body_t   *rb;
  ngx_http_core_loc_conf_t  *clcf;

  rb = r->request_body;

  if (rb->temp_file == NULL) {
    tf = ngx_pcalloc(r->pool, sizeof(ngx_temp_file_t));
    if (tf == NULL) {
      return NGX_ERROR;
    }

    clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

    tf->file.fd = NGX_INVALID_FILE;
    tf->file.log = r->connection->log;
    tf->path = clcf->client_body_temp_path;
    tf->pool = r->pool;
    tf->warn = "a client request body is buffered to a temporary file";
    tf->log_level = r->request_body_file_log_level;
    tf->persistent = r->request_body_in_persistent_file;
    tf->clean = r->request_body_in_clean_file;

    if (r->request_body_file_group_access) {
      tf->access = 0660;
    }

    rb->temp_file = tf;
  }

  n = ngx_write_chain_to_temp_file(rb->temp_file, body);

  /* TODO: n == 0 or not complete and level event */

  if (n == NGX_ERROR) {
    return NGX_ERROR;
  }

  rb->temp_file->offset += n;

  return NGX_OK;
}


ngx_int_t
ngx_http_discard_request_body(ngx_http_request_t *r)
{
  ssize_t       size;
  ngx_event_t  *rev;

  if (r != r->main || r->discard_body) {
    return NGX_OK;
  }

  if (ngx_http_test_expect(r) != NGX_OK) {
    return NGX_HTTP_INTERNAL_SERVER_ERROR;
  }

  rev = r->connection->read;

  ngx_log_debug0(NGX_LOG_DEBUG_HTTP, rev->log, 0, "http set discard body");

  if (rev->timer_set) {
    ngx_del_timer(rev);
  }

  if (r->headers_in.content_length_n <= 0 || r->request_body) {
    return NGX_OK;
  }

  size = r->header_in->last - r->header_in->pos;

  if (size) {
    if (r->headers_in.content_length_n > size) {
      r->header_in->pos += size;
      r->headers_in.content_length_n -= size;

    } else {
      r->header_in->pos += (size_t) r->headers_in.content_length_n;
      r->headers_in.content_length_n = 0;
      return NGX_OK;
    }
  }

  r->read_event_handler = ngx_http_discarded_request_body_handler;

  if (ngx_handle_read_event(rev, 0) != NGX_OK) {
    return NGX_HTTP_INTERNAL_SERVER_ERROR;
  }

  if (ngx_http_read_discarded_request_body(r) == NGX_OK) {
    r->lingering_close = 0;

  } else {
    r->count++;
    r->discard_body = 1;
  }

  return NGX_OK;
}


void
ngx_http_discarded_request_body_handler(ngx_http_request_t *r)
{
  ngx_int_t                  rc;
  ngx_msec_t                 timer;
  ngx_event_t               *rev;
  ngx_connection_t          *c;
  ngx_http_core_loc_conf_t  *clcf;

  c = r->connection;
  rev = c->read;

  if (rev->timedout) {
    c->timedout = 1;
    c->error = 1;
    ngx_http_finalize_request(r, NGX_ERROR);
    return;
  }

  if (r->lingering_time) {
    timer = (ngx_msec_t) (r->lingering_time - ngx_time());

    if (timer <= 0) {
      r->discard_body = 0;
      r->lingering_close = 0;
      ngx_http_finalize_request(r, NGX_ERROR);
      return;
    }

  } else {
    timer = 0;
  }

  rc = ngx_http_read_discarded_request_body(r);

  if (rc == NGX_OK) {
    r->discard_body = 0;
    r->lingering_close = 0;
    ngx_http_finalize_request(r, NGX_DONE);
    return;
  }

  /* rc == NGX_AGAIN */

  if (ngx_handle_read_event(rev, 0) != NGX_OK) {
    c->error = 1;
    ngx_http_finalize_request(r, NGX_ERROR);
    return;
  }

  if (timer) {

    clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

    timer *= 1000;

    if (timer > clcf->lingering_timeout) {
      timer = clcf->lingering_timeout;
    }

    ngx_add_timer(rev, timer);
  }
}


static ngx_int_t
ngx_http_read_discarded_request_body(ngx_http_request_t *r)
{
  size_t   size;
  ssize_t  n;
  u_char   buffer[NGX_HTTP_DISCARD_BUFFER_SIZE];

  ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                 "http read discarded body");

  for ( ;; ) {
    if (r->headers_in.content_length_n == 0) {
      r->read_event_handler = ngx_http_block_reading;
      return NGX_OK;
    }

    if (!r->connection->read->ready) {
      return NGX_AGAIN;
    }

    size = (r->headers_in.content_length_n > NGX_HTTP_DISCARD_BUFFER_SIZE) ?
        NGX_HTTP_DISCARD_BUFFER_SIZE:
        (size_t) r->headers_in.content_length_n;

    n = r->connection->recv(r->connection, buffer, size);

    if (n == NGX_ERROR) {
      r->connection->error = 1;
      return NGX_OK;
    }

    if (n == NGX_AGAIN) {
      return NGX_AGAIN;
    }

    if (n == 0) {
      return NGX_OK;
    }

    r->headers_in.content_length_n -= n;
  }
}


static ngx_int_t
ngx_http_test_expect(ngx_http_request_t *r)
{
  ngx_int_t   n;
  ngx_str_t  *expect;

  if (r->expect_tested
      || r->headers_in.expect == NULL
      || r->http_version < NGX_HTTP_VERSION_11)
  {
    return NGX_OK;
  }

  r->expect_tested = 1;

  expect = &r->headers_in.expect->value;

  if (expect->len != sizeof("100-continue") - 1
      || ngx_strncasecmp(expect->data, (u_char *) "100-continue",
                         sizeof("100-continue") - 1)
      != 0)
  {
    return NGX_OK;
  }

  ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                 "send 100 Continue");

  n = r->connection->send(r->connection,
                          (u_char *) "HTTP/1.1 100 Continue" CRLF CRLF,
                          sizeof("HTTP/1.1 100 Continue" CRLF CRLF) - 1);

  if (n == sizeof("HTTP/1.1 100 Continue" CRLF CRLF) - 1) {
    return NGX_OK;
  }

  /* we assume that such small packet should be send successfully */

  return NGX_ERROR;
}
